1. Field of the Invention
The present invention relates to a device for dissuading birds from alighting on certain surfaces, and more particularly to a device that includes a rotating image for frightening the birds.
2. Description of the Prior Art
It is well known that birds often try to alight on the outer structures of buildings, such as window sashes, sills, ledges, statues, wall ridges, roof gutters, portals, bridges, towers and masts.
This alighting and resting is a nuisance in that the birds, through their droppings, dirty and damage not only the landing surface, but also all outer structures of the building that are underneath.
Due to aesthetic reasons, and also to avoid irreversible damaging of the structure material, one is often obliged to deal with frequent and expensive renovation work of the damaged parts of the building.
One of the most efficient ways of preventing this nuisance consists in covering surfaces on which birds alighting is not welcome, with a device comprising a bottom base support from which extend upwardly birds dissuasive spike elements. Such a device is described in European patent application number 0 340 108, published on Nov. 2, 1989.
Such a device, however, is not fit for larger surfaces because of cost. Additionally, for obvious reasons, such devices are not suitable for surfaces utilized by people, such as balconies. For those surfaces, other systems have been developed which work on the principle of either simulating an object which frightens the bird, such as a human-like silhouette ("scarecrow effect), or of emitting a signal (e.g. ultrasound or hyperfrequency) which is physiologically bothersome to the birds. The drawbacks of the latter system are particularly the development cost, the difficulty in calibrating a really bothering signal, and the nuisance induced for men and domestic animals next to the protected surfaces. Another drawback of both systems is that they only bother the birds which progressively get used to them, rendering the protection inefficient sooner or later.